Page 5 of 18 March 2001 Fibre Channel: Why another interface? The network approach Ethernet-based IP networks form the foundation for the Internet and most local area networks (LANs). These networks are typically used for client-server and peer-to-peer communications and are designed to allow many different types of devices to communicate with one another using a wide variety of technologies. To provide this flexibility, the hardware component of the network is relatively simple and does not include flow control and error correction capabilities, both of which tend to depend on the type of devices and network technology used. Unlike a bus, network environments are usually open, unstructured, and unpredictable. Almost any device on the network can communicate with any other device at any time. A host does not necessarily know about the other devices on the network. Because networks are designed to be extremely flexible, the burden of ensuring reliable data delivery is transferred from hardware to software. As a result, networking software running on both the originator and the recipient plays a large role in managing the data transfer, detecting errors, and performing error correction. The network approach to transferring data between computer systems and peripheral devices is radically different from the approach used with a bus. Instead of transmitting multiple bits of information simultaneously across multiple wires, networks serialize the data into packets and transmit it one packet at a time along a single wire. This serial interface is not as subject to the electrical and mechanical constraints that limit the length of the cable, making it easier to transfer data over long distances. The cable and connector requirements for a serial interface are significantly simpler and less costly. Networks provide flexible connections between multiple, dissimilar devices Ethernet Server Workstation Printer Desktop computer Desktop computer An Ethernet-based network uses a single, shared line to simultaneously transfer relatively small amounts of data between multiple, dissimilar servers and clients. p1   p2   p3   p4   p5   p6   p7   p8   p9   p10   p11   p12   p13   p14   p15   p16   p17   p18